Powered toothbrush

ABSTRACT

A powered toothbrush is disclosed wherein portion of the toothbrush head is movable about a hinge. The movable portion of the head reciprocates about that hinge through the interaction of a flexible extension of that portion containing a slot. Movable within the slot is an offset end of a rotating drive shaft connected to the power source in the toothbrush. Translation of rotation movement of the drive shaft to reciprocating movement of the hinged head is achievable in a manner that the power source is not stalled or burned out if movement of the toothbrush head is prevented or limited.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. application Ser. No. 11/079,325, filedMar. 14, 2005, now U.S. Pat. No. 7,007,332, which is a continuation ofapplication PCT/US2003/28335, filed Sep. 9, 2003, which claims thebenefit of U.S. Provisional Application 60/410,078 filed Sep. 12, 2002,all of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

As toothbrush design has evolved in an effort to improve cleaning ofteeth and gums, the complexity of toothbrushes and their functions haveincreased. Powered toothbrushes are one example of efforts to improvetooth cleaning by including one or more movable sets of cleaningelements. Another approach to improving cleansing of teeth is use of atoothbrush head that is articulated or segmented to better follow therounded curvature of teeth aligned in the human jaw.

However, little has been done to synergistically combine theseapproaches in a manner that achieves effective cleaning of all teethwhile carefully avoiding harm to the gum line. That is an object of thisinvention.

One approach to a segmented or articulated toothbrush head is shown inU.S. Pat. No. 6,314,606B1 issued Nov. 13, 2001 to Douglas Hohlbein. Thispatent disclosed a two part toothbrush head joined by a living hinge orother integrally molded elastomeric-type connector. Under one embodimentof this patent, the part of the toothbrush head most remote from thehandle is normally angled with respect to the head section nearest thehandle. According to the patent, the flexible angulation of the headaccommodates to the curvature of the human jaw, as well as therelatively straight portions of the jaw. In addition, the flexibility ofat least a portion of the head provides a more gentle treatment of thegum line because the force applied by the user is moderated and moreevenly distributed through the hinge (column 1, lines 61–67).

SUMMARY OF THE INVENTION

A powered toothbrush is disclosed which drives a moving portion of thetoothbrush head in a reciprocal motion about a hinge joining the movingportion of the head to a fixed portion of the head. The reciprocationmovement provides a power assisted tip pulsing action.

To facilitate this movement, the living hinge construction used in theaforementioned patent may be replaced with a less rigid hinge such as apivoting pin and socket joint. However, the hinge construction may be ofany type that does not affect the powered reciprocating of the movingportion of the toothbrush head.

The movable section of the toothbrush head can be powered by using thetype of drive mechanism shown in U.S. Pat. No. 5,625,916.

Another powered toothbrush is described in U.S. Pat. No. 6,347,425B1issued Feb. 19, 2002 and assigned to the assignee of this invention. Itdiscloses an electrically powered toothbrush having rotatable driveshaft with an end off-set from the central longitudinal axis of thedrive shaft which provides a reciprocating, rocking motion to a set ofcleaning elements.

In a preferred embodiment, the movable portion of the toothbrush headhas a flange extending therefrom toward the handle. This flangepreferably has a horizontal slot that accepts an offset in a drive shaftextending from the motive source in the toothbrush handle for example, amotor. This offset in the drive shaft is similar to that shown in U.S.Pat. No. 6,347,425B1 discussed above.

The slot in the flange interacts with the offset in the drive shaft toform a “slip clutch” so that if an excessive load is applied to themovable portion of the toothbrush head, the motor powering thetoothbrush will not stall. This “slip clutch” effect also has theadvantage of being a safety mechanism when in use. More particularly,the slip clutch limits operation of the movable portion of the head ifthe user applies excessive force to the handle.

The use of the flange extending from the powered portion of thetoothbrush head also permits a low profile of the toothbrush head. Thatlow, compact profile facilitates insertion and use of the toothbrush inthe human mouth.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is capable of use in a broad array of consumer packagingand products. The drawings illustrate one use of the invention and arenot to be construed as the only embodiment of the invention.

FIG. 1 is a perspective view of a power toothbrush with a power drivenmovable portion of a toothbrush head.

FIG. 2 is an enlarged cross-sectional view showing the movable portionof the toothbrush head with attached flange powered by an offset drivemechanism, in one position.

FIG. 3 is an enlarged cross-sectional view showing the movable portionof the toothbrush in another position.

FIG. 4 is an elevational view showing the slot in a tab on the flangeattached to the movable portion of the toothbrush head in alternatepositions.

FIG. 5 is an elevational view showing an alternate design of the slot onthe tab attached to the movable portion of the toothbrush head.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The powered toothbrush 10 of this invention includes a motor 12 poweredby batteries or rechargeable energy source 14. The toothbrush 10 can beoperated by depressing or otherwise operating power switch 16 on thebody of toothbrush 10.

A powered motor 12 rotates in a conventional manner. A drive shaft 18 isconnected to the motor 12 through a shaft coupling or other means ofdirectly transferring the motor's rotation to drive shaft 18.

Toothbrush 10 contains a two part articulated head 20 comprising amovable portion 22 and stationary portion 24 formed as part of theoverall powered toothbrush. Movable portion 22 preferably has a softelastomeric coating 23 which reduces the impact thereof on the usersteeth and mouth during use. These portions of head 20 are preferablyjoined by a hinge 25 that allows movable portion 22 to freely moverelative to portion 24. It is envisioned that the portion of toothbrush10 containing the head 20 could be adapted for replacement by insertinga new head into the powered portion of the toothbrush at or about thelocation indicated by reference numeral 28.

The stationary 24 and movable 22 portions of the toothbrush head 20contain cleaning elements 30. Cleaning elements 30 are arranged in bothportions of head 20 in a known manner. Any suitable form of cleaningelements may be used as the cleaning elements 30 in the broad practiceof this invention. The term “cleaning elements” is intended to be usedin a generic sense which could include conventional fiber bristles ormassage elements or other forms of cleaning elements such as elastomericfingers or walls arranged in a circular cross-sectional shape or anytype of desired shape including straight portions or sinusoidalportions. Where bristles are used, the bristles could be mounted to tuftblocks or sections by extending through suitable openings in the tuftblocks so that the base of the bristles is mounted within or below thetuft block.

It is to be understood that the specific illustration of the cleaningelements is merely for exemplary purposes. The invention can bepracticed with various combinations (such as stapled or in-moldtechnology bristles, etc.) and/or with the same bristle or cleaningelement materials (such as nylon bristles, spiral bristles, rubberbristles, etc.) Similarly, while the Figures illustrate the cleaningelements to be generally perpendicular to head 20, some or all of thecleaning elements may be angled at various angles with respect to thesurface of head 20. It is thereby possible to select the combination ofcleaning element configurations, materials and orientations to achievespecific intended results to deliver additional oral health benefits,like enhanced cleaning, tooth polishing, tooth whitening and/ormassaging of the gums.

The changes in orientation of movable portion 22 during operation arebest understood by comparing FIGS. 2 and 3. Movable portion 22 has aflange 26 attached thereto extending from the area of movable portion 22adjacent the last row of cleaning elements and extending lengthwisetoward the drive shaft 18. This flange 26 may be molded as part ofmovable portion 22 or affixed thereto. The flange 26 terminates at a tab32 which is preferably aligned approximately perpendicular to the axisof drive shaft 18.

Tab 32 at the end of flange 26 contains a slot 34 for receipt of anoffset end 36 or elbow of drive shaft 18 (See FIGS. 2 and 4). As driveshaft 18 rotates unidirectionally under motor power the offset end 36 ofthe shaft 18 engages the side edges of slot 34. This causes the flange26 to rotate counterclockwise around hinge 25 from a positionimmediately adjacent the back side 27 of the stationary portion 24 ofhead 20 (FIG. 2) to a position 15–30 degrees (angle θ) from thatposition 6 (FIG. 3). As the drive shaft rotates, typically at severalhundred revolutions per minute, movable portion 22 of head 20 rapidlymoves about hinge 25 resulting in a vigorous passage of cleaningelements 30 over the user's teeth and gums. This rapid movement helps toclean the user's teeth and stimulate the user's gums.

FIGS. 4 and 5 illustrate alternative configurations 34 and 34A for slot34. Slot 34 of FIG. 4 is closed at both ends to contain the offset end36 of shaft 18 whereas slot 34A shown in FIG. 5 allows movement ofoffset end 36 across the entire width of tab 32 attached to flange 26.

Flange 26 is preferably formed of a moderately flexible material thatpermits its movement independent of movable portion 22 of the toothbrushhead 20. Thus, if the user applies considerable force on the end ofmovable portion 22, that tends to keep it in the position shown in FIG.4 while drive shaft 18 is turning, the flexibility of flange 26 willallow the motor to continue turning even though the movable portion 22of head 20 is not moving or only slightly moving. This flexibility inflange 26, coupled with the slot 34 or 34A in tab 32, prevents stallingof motor 12 in those situations where unusual pressure is exerted on themovable portion 22 of head 20.

Under normal operation tab 32 will be displaced in a plane perpendicularto the axis of the toothbrush, and the drive shaft 18, as the offset end36 of that shaft rotates with the shaft. The amount of movement of tab32, and consequent movement of movable portion 22 can be regulated bythe distance between the axis of drive shaft 18 and the offset end 36 ofthat shaft. FIG. 4 illustrates this movement as the drive shaft 18 movesto opposite extremes of rotation. The full lines in FIG. 4 represent theplacement of tab 32 when movable portion 22 of head 20 is in theposition shown in FIG. 2. The phantom lines correspond to its positionwhen movable portion 22 is in the FIG. 3 position.

To improve the cleansing of toothbrush 10 and preserve the operatingparts 18, 26 and 32 from corrosion and or contamination, a cover 38 isplaced over these parts. The cover 38 is preferably flexible or moldedto allow free movement of flange 26 under power of drive shaft 18.

1. A powered toothbrush comprising: a power source; a rotatable driveshaft having a first end operatively connected to the power source, anda second end; and a toothbrush head having a stationary portion and amovable portion flexibly connected to the stationary portion, eachportion having cleaning elements extending therefrom, the movableportion being operably connected to the second end of the drive shaft;wherein the movable portion includes a flexible flange having an offsetend from a longitudinal axis of the flange and the offset end isoperably connected to the second end of the drive shaft.
 2. The poweredtoothbrush of claim 1, wherein the movable portion of the toothbrushhead is hinged to the stationary portion of the toothbrush head.
 3. Thepowered toothbrush of claim 1, wherein the movable portion of thetoothbrush head includes a soft elastomeric coating.
 4. The poweredtoothbrush of claim 1, further comprising a cover overlaying the driveshaft and the flexible flange.
 5. The powered toothbrush of claim 4,wherein the cover is made of a flexible material.
 6. The poweredtoothbrush of claim 4, wherein the cover is molded in a shape whichpermits free movement of the drive shaft and flexible flange therein. 7.A powered toothbrush comprising: a power source; a rotatable drive shafthaving a first end operatively connected to the power source, and asecond offset end; and a toothbrush head having a stationary portion anda movable portion flexibly connected to the stationary portion, eachportion having cleaning elements extending therefrom; wherein themovable portion of the toothbrush head reciprocates about an axis thatis lateral to a longitudinal axis of the toothbrush head across a frontface of the toothbrush head as the second offset end of the drive shafttravels; wherein the movable portion includes a flexible flange operablyconnected to the second offset end of the drive shaft.
 8. The poweredtoothbrush of claim 7, wherein the movable portion of the toothbrushhead is hinged to the stationary portion of the toothbrush head.
 9. Thepowered toothbrush of claim 7, wherein the movable portion of thetoothbrush head includes a soft elastomeric coating.
 10. The poweredtoothbrush of claim 7, further comprising a cover overlaying the driveshaft and the flexible flange.
 11. The powered toothbrush of claim 10,wherein the cover is made of a flexible material.
 12. The poweredtoothbrush of claim 10, wherein the cover is molded in a shape whichpermits free movement of the drive shaft and flexible flange therein.